New synthetic vitamin D analogs with antiproliferative activities

The introduction of oxygen atoms into different positions of the vitamin D side chain is described. By combining the arising 23-oxa and 25-oxa element s with other structural modifications (19-nor, iso-19-nor, 20-methyl, 20-en e, 20,21-cyclo) calcitriol analogs with remarkable levels of dissociation b etween beneficial acitivities on cell growth regulation and undesired hyper calcemia were identified. Structure-activity relations are elaborated in a very systematic outline of the Schering drug finding program in this partic ular class of vitamin D compounds.